CYTOPLASMIC MALE STERILITY (CMS) BASED HETEROSIS AND GENE ACTION STUDIES IN CAULIFLOWER (Brassica oleracea L. var. botrytis L.)
Loading...
Date
2019-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSK HPKV, Palampur
Abstract
The present investigation was undertaken to assess the combining ability, nature and magnitude of gene action and to ascertain best heterotic combinations for morpho-physiological, yield and yield contributing and quality traits. Forty eight cross combinations developed by crossing eight CMS lines and six diverse testers in Line × Tester fashion were evaluated along with four standard checks in randomized complete block design with three replications at the Vegetable Research Farm, CSK HPKV, Palampur and HAREC, Bajaura, Kullu during winter 2017-18. Visual, morphological (Ward’s method) and molecular characterization (SSRs) were employed to assess the diversity in parental materials. Out of 35 SSRs, 28 were found to be polymorphic and PIC value ranged from 0.17 to 0.54 with an average of 0.37. The PCoA, PCA and factor analysis delineated the CMS lines into two groups as mid-maturity (CaYCMS-1, CaYCMS-2, CaYCMS-3, CaYCMS-4 and CaYCMS-5) and late group (CaYCMS-6, CaYCMS-7 and CaYCMS-8) CMS lines. All the CMS lines showed similar performance as that of their maintainers for seedling, floral and seed traits. Results of combining ability were discussed by analysing the data in all three possibilities as Experiment I (All CMS lines and testers), Experiment II (5 Mid-late group lines and testers) and Experiment III (3 Late group lines and testers). The bifurcation of experiment reveals the importance of late group lines in terms of earliness and mid-group lines for yield and related traits when analysed for GCA. Thus lines and testers showing good GCA, crosses with good SCA and heterosis in Experiment II and Experiment III were given prime importance. The analysis of variance indicated significant differences among genotypes for most of the traits in both the experiments under all the environments, exhibiting wealth of variability. Location × genotype interaction was significant for most of the traits which indicated a definite role of environment on the performance of genotypes. The line × tester analysis revealed significant differences due to lines, testers and line × tester interaction indicating appreciable diversity in the experimental material. The parental lines viz., CaYCMS-3 and CaYCMS-5 in Experiment II and CaYCMS-6 in Experiment III while testers viz., DPCaY-6, DPCaY-7 and DPCaY-8 in Experiment II and DPCaY-3, DPCaY-5 and DPCaY-9 in Experiment III were identified as good general combiners for earliness and most of the morpho-physiological traits. Among lines CaYCMS-4 and CaYCMS-5 in Experiment II and CaYCMS-7 in Experiment III and testers viz., DPCaY-6 and DPCaY-9 in Experiment II and DPCaY-6, DPCaY-8 and DPCaY-9 in Experiment III were the good general combiners for yield and yield related traits. For quality traits, lines CaYCMS-1, CaYCMS-2 and CaYCMS-5 in Experiment II and CaYCMS-6 and CaYCMS-8 in Experiment III and testers DPCaY-5, DPCaY-6 and DPCaY-7 in Experiment II and DPCaY-5, DPCaY-6 and DPCaY-9 in Experiment III were identified as good general combiners. Non-additive gene action was in preponderance for most of the traits suggesting the exploitation of hybrid vigour in cauliflower. On the basis of GCA, SCA and heterosis, CaYCMS-3 × DPCaY-7 and CaYCMS-3 × DPCaY- 8 in Experiment II and CaYCMS-8 × DPCaY-8 and CaYCMS-8 × DPCaY-9 in Experiment III had appreciable tendency for early maturity across the environments. Crosses viz., CaYCMS-1 × DPCaY-7, CaYCMS-5 × DPCaY-5 and CaYCMS-5 × DPCaY-6 in Experiment II and CaYCMS-6 × DPCaY-8 from Experiment III were observed as promising combination for most of quality traits. For marketable yield, CaYCMS-5 × DPCaY-9 (265.19 q/ ha) and CaYCMS-5 × DPCaY-5 (261.98 q/ ha) from Experiment II and CaYCMS-6 × DPCaY-6 (336.54 q/ ha) and CaYCMS-7 × DPCaY- 7 (329.40 q/ ha) from Experiment III were the most promising cross combinations across the environments. The cross combination CaYCMS-5 × DPCaY-5 also showed appreciable heterosis for dry matter content, TSS, K and Mg. These best performing hybrids could be recommended for release after thorough evaluation over the environments. Further, mid-maturing and late maturing CMS lines can be used for developing hybrids that can mature in succession and provide continuous harvest to the farmers for fetching higher prices in the market. Moreover, separate analysis is recommended for different maturity groups in cauliflower for drawing unbiased conclusions even if the genotypes of different groups were transplanted at same time.
Description
Keywords
null